Chapter 21 is entirely Luke’s dialogue as he tells Clary the history of himself, her mother, Valentine, and the Shadowhunters. Luke, Valentine, and Clary’s mom attended school together, where Clary’s mom and Valentine excelled while Luke struggled. Valentine tutored Luke, who improved with his help, and Luke gave his allegiance to Valentine, feeling like he owed him everything. Valentine similarly helped Hodge, the Lightwoods, and others, and looking back, Luke is sure Valentine was building a cult following. Valentine believed the Shadowhunters were dying out and that their teachers were lying when they said most humans couldn’t survive drinking from the Mortal Cup. He and his followers formed a coalition with the goal to “save the race of Shadowhunters from extinction” (391).

Valentine’s father was killed by werewolves, and after that Valentine became angry and cruel. Clary’s mom felt badly for him, and the two fell in love. After the group graduated, Valentine expanded his mission to include ending all Down-worlders. Sometime later, Clary’s mom got pregnant and confessed to Luke she was afraid of Valentine. Luke spoke to Valentine about her fears, but Valentine brushed them off and invited Luke to hunt werewolves, which was the night Luke was turned.